Grinding, polishing, and featheredging tool



C. P. RHEES GRINDING, POLISHING, AND FEATHER-EDGING TOOL Sept. 11, 1951 Filed Sept. 19, 1949 'INVENTOR. 09PM P. EHEES.

slippage.

Patented Sept. 11, 1951 GRINDING, POLISHING, AND FEATHER- EDGING TOOL Carm P. Rhees, Staten Island, N. Y.

Application September 19, 1949, Serial No. 116,438

This invention relates to a grinding, polishing and feather-edging tool. 7

' Portable, motor-driven grinding, polishing and feather-edging tools and attachments are well known in many industries, including the motor 3 Claims. (01. 51-197) Vehicle body building and repairing industry.

These tools and attachments are available in many forms and types. The kind of tool to which the present invention applies makes use of relatively large grinding, polishing and featheredging discs which are removably and replaceably mounted thereon. It is generally used in motor vehicle body repair work, as, for example,

where a suitable metallic compound is applied for fill-in purposes, or where torn body parts are welded together, or where touch-up work is done.

One of the important requirements of this type of tool, especially for polishing and featheredging operations, is that there be suflicient slippage between the polishing or feather-edging disc and the carrier on which it is mounted.

Another important requirement of this type of tool is that it be provided with suitable fas-,

tening means for holding the grinding, polishing and feather-edging discs thereon for the full useful life of said discs.

Still another important requirement is that each disc be individually mountable and demountable with respect to the tool for as many timesas may be necessary to derive the fullest use and benefit therefrom in accordance with conventional shop practices. A given disc, for example, may be used rather sparingly'on any one occasion, and it is important that said disc be removable from the tool and replaceable thereon as many times as may be necessary during the course of its normal life span.

The prior art discloses no grinding, polishing and feather-edging tool of this general character wherein all of the requirements above mentioned, as well as other requirements, are fully met. In some cases, the fault lies with the tool itself; in most cases, the fault lies with the type of grinding, polishing or feather-edging disc used. The fastening means whereby the discs are fastened to the tool either provide for no slippage of the discs whatsoever or for excessive The discs themselves are much too weak in the area of their engagement with the fastening means so that distortions and tears frequently take place long before the full useful life of the discs is expended. Although the discs are designed for mounting on the tool and removing therefrom as many times as may be necessary, frequently a single use thereof is sufii- -cient to preclude and prevent any further use thereof.

'It is accordingly the principal object of this invention to provide a grinding, polishing and feather-edging tool of they character described time it securely holds the disc on the tool without damage or injury to that part of the disc which it engages. The disc is provided with a reinforcing member or attachment in said area of its engagement with the disc-fastening means so that the danger of damage or injury to the disc in that area is still further lessened or removed. And finally, the disc-fastening means and the disc reinforcing member are so designed that the disc may be securely mounted upon said fastening means by simply snapping it on said fastening means, and it may very readily be removed therefrom by simply snapping it off said fastening means.

More specifically, the disc-fastening means of the present invention comprises a button-shaped member which has a disc-engaging head and a reduced neckwhich carries the disc, and a tension member which presses the disc against said disc-engaging head. The strength of the tension member determines the frictional coeflicient between the disc and the disc-engaging head of the button-shaped member. It will hereinafter be seen, however, that this tension member is not the only means which controls slippage of the disc. The disc-reinforcing attachment of the present invention comprises at least one and preferably two relatively small ring-shaped reinforcements which are placed on both sides of the disc, one of them between the operative side of the disc and the disc-engaging head, and the other between the inoperative side of the disc and the tension member. These reinforcements may be secured to the disc or they may merely be juxtaposed to the disc. Preferably, however, at least one of the reinforcing rings should be fastened to the disc and that is the ring which is on the inoperative side of the disc. Each reinforcing ring is made of relatively stiff material but its inner edge is weakened in some way, as by means of notches, to render it sufficiently flexible to slip over the button-shaped member of the'disc-fastening means, either to mountthe disc thereon or to remove it therefrom.

A preferred form of this invention is shown in the accompanying drawing, in which:

' Fig. 1 is an exploded, perspective view of a tool incorporating the features of the present invention.

Fig. 2 is an enlarged diametrical. section through the operating head of the tool, showing all of the parts thereof in assembled condition,

back' or inoperative side;

' is a reduced neck portion 2|.

including the disc, its two reinforcing rings, the button-shaped disc holder on which said disc and its reinforcing; rings are mounted; and the'tension member which holds said discand said reinforcing rings tight against said button-shaped disc holder.

Fig. 3 is a fragmentary face view of .oneof. saiddiscs and disc reinforcing rings, shown mounted upon a button-shaped disc holder made in accordance with the present invention.

Fig. 4 is a face view or plan view. ofoneofthe reinforcing rings.

Fig. 5 is an edge view of a sand or emerypaper" disc, showing a reinforcing member secured to its Fig.- 6 showstwo such discs fastened back'to backwith one of said reinforcing rings mounted between them.-

Fig: 7 is another edge'viewof a polishing or buffing disc orattachment, showingareinforcing 0 member secured to its back or inoperative side.

Fig.- 1 shows a. motor driven tool I 0' to which th'e present invention maybe-applied. It-has a drive shaft H and a molded rubber pad I2 or any othersuitable pad of resilient ornon-resil- 2r; ient material.- It will be seen in Fig. 2 that the drive shaft or spindle I I is provided with external screw threads and that pad I2 is provided with a-tapped hole E3 to receive said threaded shaft. Thus-far the construction is conventional.

Disc-holding member l5 -isa tubular member which is provided with internal screw threads l6. It is adapted to be mounted upon threaded shaft II in screw-threaded engagement therewith as.- Fig. 2 clearly shows. It accommodates a socket 35 type of set screw or plug I! which abuts. the end of the drive shaft to lock the disc-holding member in place thereon. This arrangement is also conventional.

Disc'holder l5-has an annular beador lip 40 formed thereon, peripherally thereof, at-its.forward" or leading end. Behind said annular bead, which is, or may be described as, of button shape, Behind the neck portionZl is an annular flange-22 which extends radiallyv outwardly from the main body of :said tubular: disc holder 15.- Behindflange 22 isa reduced end portion 23 which extends to-the very back end of said tubular disc holder.

Pad [2 has an annular recess 2-5 which: is adapted to accommodate endportion 23 of the discholder when both the disc holder and said pad are securely mounted on the drive shaft of said motor driven tool- 10. The pad. also has. another annular recess 26 which is relatively shallow and which surroundsits first-mentioned recess- 25. The dimensions of recess-25 -and end portion 23 are such thatthere is a relatively snug fit between the-pad and said end portion 23 of the disc holder and the depth of recess 26 is such as to prevent flange 22 of the disc holder from engaging the face of the pad.

The tool is provided with a second pador backing-,30"which rests, againstthe face of moldedv pad. l2. Pad'or-backing 3D comprises-a fiber disc 65 3| and acushion 32:secured*thereto -whichis made of felt or other suitable material. The fiber back 3| has a hole 32 formed therein, centrally thereof, and the diameter of said hole is but slightly larger than the diameter of endpor- 7 tion 23 of the disc holder. It is possible, therefore, .to mount said fiber back 3| on end portion 23 .as Fig. 2 clearly shows. A centrallyextending 1101c. fis .formedlin cushion. 32 whichis.=con- 0 .eter of necks2i -of--the. disc. holder.

fiber back and also considerably larger in diameter than flange 22 of the disc holding member l5: It'is, therefore, possible to: mount pad or backing 3:]..upon the disc holder .insuch manner that back 3| occupies a position between flange 22 on the one hand and the face of molded pad 12 .onthe other hand. A certain amount of tension maybeincorporated into fiber back 3| by simply tightening the disc holder [5 upon the drive shaft II; This has the effect of pushing or drawingthe .center of back 3| into the shallow annular recess 26"which is formed in the face of molded pad 12.

Molded pad l2 functions in the manner of a back support .with..respect tobacking or pad-. 30. Said backing or pad 30.functions.in..the' manner of a backing-or-support fordisc .35'whichis shown in Figs. 1, 2, 3 -and-5;- It may. also serve.as. a backing for doubledisc 36showninFig. 6 aswell as for disc orattachment 3 5 shown in Fig. 7. The frictional engagement between these discsand backing 3t aswell as the action .of .the .tension member above mentioned, .determine the extent of slippage of the discs, cont-rolled, of course, by the. pressure applied .totheworlz- Disc- -is-known-as. a featheredging disc- It comprises a paper disc lilcoated on its.-face.with emery dust or granules. 4| andv provided withla centrally disposed hole 42. AsFig. 2 shows,- this hole 42 corresponds in diameter. tonecknll of the disc holder, and-hence itsudiameterissomewhat smaller thanthe diameterof button-shaped end portion or bead w of saiddisc holder. It is necessary, therefore, that theinner edgeof the disc immediately;surroundingrits central hol'e yield sufficiently to enablethe dicsito passover the button-shaped endportionlflnin either. direction.

As appears from Fig. 5,. areiniiorcing-ring. may be mounted on thetbackor.inoperativeside of the disc. In the preferred: form of thiswinvention, the reinforcing. ring. is secured to the back of the disc bymeans of a suitablev cement or other suitable fasteninginea-ns. This .rein-F forcingring-is made. of relativelyjstiff material, suchas pressed fiberboard, andithasacentrally situated holefifisfor-med therein, the diameterof said hole: corresponding to thediameter of hole 42 in disc35; and also correspondingto thediam- N otches All are formed. in and alongthe inneredge of -reinforcing rin 45 :to provide =said inner edge. with a-certain amountof'fiexibility. It is thisflexibilitywhich enables the reinforcing ring. to pass 5 over the button-shapedend portion20 of -the disc holder. It isde'sirable touse tworeinforcing rings for eachdisc,..one--being.. situated at .the back of: the discandtheother being .situated :in front of the disc. Both reinforcing members maybesecured to the :disc, .or-onlyone of them, or neither of them Preferably; however, at least one reinforcingmember:iscsecured to the. disc and. that is the one-which is .situatedat the back ofzthe disc. See Fig. 5. Fig.- IshoWsCnei-ther of. the two reinforcingmembers affixedto. the

disc.

A tension memberEIJ-maybemOunted-on neck portion-2! of-the-discliolder. This vtensionmemher which; preferably,- is acoi-led-.- compression spring, bears at itsback: endiagainst flange.-22

siderably larger in diameter than hole 33 in the firmly against the reinforcing rin which is situated in the front of said disc and it also causes said front reinforcing ring to press tightly against the button-shaped forward end of the disc holder. A frictional coemcient is thereby achieved which assists in preventing slippage of the disc relative to the disc holder. When the disc is pressed against the work, additional friction is generated between the back of the'disc and the face of the backing or pad 39 to further reduce the possibility of slip-page of the disc. Some slippage will take place, however, when the disc is pressed firmly or tightly against the work, but such slippage is both desirable and necssary, especially for feather edging. When such slippage takes place, the front reinforcing ring prevents the emery of the disc from wearing away the button-shaped forward end of the disc holder.

The grinding disc shown in Fig. 6 differs from the feather edging disc shown in Fig. 5 in that it comprises a double disc with a reinforcing ring in the middle. Disc 36 comprises two emery discs 52 and 53, respectively, which are disposed back to back, with a reinforcin ring between them. They may be secured to the reinforcing ring by means of cement or any other suitable fastening means. Since the emery side of one of the discs 52 and 53 bears against the padding or cushion 32 of backing 39, and the emery side of the other of said discs bears against the work,

considerable friction will be generated both between the first-mentioned disc and the cushion, and between the second-mentioned disc and the work, before any slippage of said discs relative to the disc holder will take place. In the preferred use of grinding disc 36, three reinforcing rings should be used. the reinforcing ring which is secured between the two discs 52 and 53, one reinforcing ring on the emery side of disc 52, and another reinforcing ring on the emery side of disc 53.

The polishin or bufiing disc shown in Fig. '7 includes a backing 55 which may be made of pressed fiberboard, and a buffing pad 56 which may be made of any suitable bufing material. If desired, disc 31 may be made of sheepskin, the skin or leather thereof constituting backing 55 and the hair, pile or fur thereof constituting the padding 5%. A reinforcing ring may be attached to the back of disc 23'! and another ring may, if desired, be placed in front of said disc.

The foregoing is descriptive of a preferred form of this invention, and it will clearly be understood that other forms of the invention and modifications of the instant form may readily be had within the broad scope and coverage of the invention. For example, if the paper or other material of which the discs are made, is sufficiently strong, there will be no need to apply a reinforcing ring thereto. In such case, the inner edge of the disc should be sufliciently inflexible so as to render it necessary to use force to snap it over the button and yet sufliciently flexible so that it can be snapped over the button without great difiiculty. Hence, notches similar to the notches formed in the reinforcing ring should be formed in the disc to give its inner edge that required flexibility and resilience for which the present invention calls.

The notched inner edge of the reinforcing member merely illustrates an inner edge which is sufliciently yielding and resilient for the purposes of the present invention. Notches are generally required in relatively stiff material such as fibre board, but it would not be necessary to provide notches in somewhat more elastic material, such as synthetic rubber or textile fabric. Hence when elastic materials are used either in the disc itself or in the reinforcing ring, there will be no need to notch their respective inner edges to provide the resilience which they already have. Broadly speaking, therefore, any disc which is provided with a snap-0n feature or facilities which would enable it to snap over the buttonshaped disc holder, would meet the requirements of the present invention and come within its scope. This is true whether the disc has or has not a reinforcing ring, and whether the disc or its reinforcing ring is or is not notched, and whether, if notched, the notches are similar or not similar to the notches shown in the drawing.

The invention is also sufficiently broad to encompass a button-shaped disc holder wherein the button comprises an annular flange which is continuous a full 360 (as shown in the drawing) as well as an interrupted flange or a plurality of disc or disc reinforcement engaging bosses or projections.

Having thus described my invention, What I claim as new and desire to secure by Letters Patent, is:

1. A feather-edging, grinding and polishing tool of the character described, having a disc holder and a disc removably mounted on said disc holder, said disc holder having an enlarged annular end portion, a reduced neck behind said end portion which carries the discsaid reduced neck being circular in cross secti0nto provide a yielding frictional drive between said disc holder and said disc, and an annular flange behind neck portion, a compression spring being provided between the flange and the disc to press said disc against the enlarged end portion.

.2. A feather-edging, grinding and polishing tool in accordance with claim 1, wherein a reinforcing ring is disposed on the disc between said disc and the spring and wherein a second reinforcing ring is disposed on the disc between said disc and the enlarged end portion of the disc holder.

3. A feather-edging, grinding and polishing tool of the character described, having a disc holder and a disc removably mounted on said disc holder, said disc holder having an enlarged annular end portion, a reduced neck behind said end portion which carries the disc, and an annular flange behind said neck portion, a compression spring being provided between the flange and the disc to press said disc against the enlarged end portion, a fibre backing plate behind said annular flange, a cushion disc secured to the front of said backing plate, said cushion disc having an axial opening therethrough, the diameter of which is considerably larger than the diameter of said flange.

CARM P. RHEES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 478,881 Moore July 12, 1892 503,258 Stanbrough Aug. 15, 1893 802,136 Busfield Oct. 17, 1905 1,736,098 Stever Nov. 19, 1929 2,125,742 Sundhauss Aug. 21, 1938 

